The two vulnerable women were discovered strangled and burned in their flats less than 100 yards apart in Hastings, East Sussex, in January 1998.

At Lewes Crown Court, Fisher was given the indeterminate prison sentence after he admitted attempting to murder and trying to rape a student on a train in the same month as the killings.

Fisher also pleaded guilty to two counts of rape of another vulnerable woman in her early 40s at her home in Bromley, south east London, in 1991.

He confessed to the offences while being held at the high-security psychiatric hospital two years ago after saying he found it hard to live with his crimes, the court heard.

After the sentencing, Detective Chief Inspector Trevor Bowles, of Sussex Police's major crime branch, said: ``This was a long and complex investigation, which was first re-examined in 2007.

``A review of the case followed and it was during this period that Fisher's admissions in Broadmoor began.

``The six offences to which Fisher pleaded guilty demonstrate the extreme danger he poses to the public. His offences have wrecked the lives of many individuals and families.

``We worked closely with the complex case unit of the Crown Prosecution Service and I am grateful to them and to our leading counsel, Richard Barton, as well as my investigative team, who have all shown the passion and desire to seek justice for Fisher's victims.''